1. Field of Invention
The invention described herein applies to leveraged tools.
More particularly the invention described herein applies to leveraged tools for releasing or applying springs.
More particularly this device applies to inventions for tensing brake springs onto truck brakes in a vehicle having a bar in the brake for applying the spring.
2. Prior Art
The prior art shows several inventions directed to the application of brake springs using leverage.
These provide for notches or ridges for attaching the spring prior to applying the spring by way of a notch attached to a lever.
Several of these inventions are potentially adaptable to applying brake springs to trucks or are directed towards that end.
The prior art shows several devices for applying or removing brake shoes. Examples are 2,666,256 issued to White, 2,839,820 issued to Bater, and 4,063,342 issued to Mitchell.
As shown in Vectin 2,685,731 4,063,342 issued to Mitchell the concept of a grooved slot for receiving a spring coil is old art. Several patents such as 2,321,263 show a leveraged arm to apply a
This prior art envisions a spring intended to be mounted on an anchor pin. Cranks have been used in order to lift the spring into position as with U.S. Pat. No. 2,839,820 where the crank serves to rotate around the axis of the anchor pin. This requires the pin be open for receiving the crank. There is a separate arm for receiving the spring. The lever must be put in place in a narrow area after the staff is put in place on the pin.
The devices available in the prior art for tensing and applying brake shoes discussed above do not provide all of the features necessary to easily change brake shoes on trucks.
Because these require fairly regular service, there has been a long need for a product which would allow for the easy removal in a wide range of locations.
Another major difficulty with the prior art is the need to manipulate, at a distance, moving parts. Another difficulty not solved is the inability of existing spring tensing devices to be inserted around an existing hardware to put the spring in place.
One of the major problems with the prior art is that it does not allow for the lever arm to be easily placed on the recessed spring mounting arm which is typically behind metal plates. The metal plates may serve to prevent the spring from becoming dislodged during operation and in order to serve as a mounting place for the bar to which the spring attaches.
Another problem with the prior art is that it is difficult to learn to use.
Another problem with the prior art is inability to raise the spring in a way where the spring does not interfere with the raising means.